Add plugin system

README.md

@@ -106,6 +106,25 @@ ember status
 
 Ember polls the Caddy admin API and Prometheus metrics endpoint at a regular interval (default: 1s), computes deltas and derived metrics (RPS, percentiles, error rates), and renders them through one of several output modes: an interactive [Bubble Tea](https://github.com/charmbracelet/bubbletea) TUI (default), streaming JSONL, a headless daemon with Prometheus export, or a one-shot `status` command.
 
+## Plugins (experimental)
+
+Ember supports a plugin system that lets third-party developers add custom tabs for visualizing metrics from additional Caddy modules (e.g., rate limiters, WAF modules, custom middleware). Plugins are compiled into the binary using Go's blank import pattern, the same approach used by Caddy itself.
+
+Building a custom Ember binary with plugins is simple:
+
+```go
+import (
+    "github.com/alexandre-daubois/ember"
+    _ "github.com/myorg/ember-myplugin"
+)
+
+func main() { ember.Run() }
+```
+
+Plugins can provide multiple tabs, subscribe to core metrics, conditionally hide their tabs, and reuse Ember's Prometheus parser via the `pkg/metrics` package.
+
+See the [Plugin Development Guide](docs/plugins.md) for details on building and integrating plugins.
+
 ## Documentation
 
 Full documentation is available in the [docs/](docs/index.md) directory:
@@ -119,6 +138,7 @@ Full documentation is available in the [docs/](docs/index.md) directory:
 - [Prometheus Export](docs/prometheus-export.md): Metrics, health checks, daemon mode
 - [Docker](docs/docker.md): Container usage
 - [Agent Skills](docs/skills.md): Skills for AI coding agents
+- [Plugins](docs/plugins.md): Building custom plugins for Ember (experimental)
 - [Troubleshooting](docs/troubleshooting.md): Common issues and solutions
 
 ## Contributing

cmd/ember/main.go

@@ -4,13 +4,14 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/alexandre-daubois/ember/internal/app"
+	"github.com/alexandre-daubois/ember"
 )
 
 var version = "1.0.0-dev"
 
 func main() {
-	if err := app.Run(os.Args[1:], version); err != nil {
+	ember.Version = version
+	if err := ember.Run(); err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}

demo-traffic.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+#
+# Generates traffic against the local Caddy/FrankenPHP setup
+# for demo purposes (Ember TUI recording).
+#
+# Usage: ./demo-traffic.sh [duration_seconds] [concurrency]
+# Default: 60 seconds, 8 concurrent workers
+#
+# Requires: curl
+
+set -euo pipefail
+
+DURATION=${1:-60}
+CONCURRENCY=${2:-8}
+
+MAIN="https://localhost"
+APP="https://app.localhost:8443"
+API="https://api.localhost:9443"
+
+ROUTES=(
+    "$MAIN/"
+    "$MAIN/"
+    "$MAIN/"
+    "$MAIN/blog/"
+    "$MAIN/blog/"
+    "$MAIN/blog/page/1"
+    "$MAIN/blog/rss.xml"
+    "$MAIN/blog/search?q=lorem"
+    "$MAIN/login"
+
+    "$APP/"
+    "$APP/"
+    "$APP/blog/"
+    "$APP/blog/page/1"
+    "$APP/blog/search?q=test"
+
+    "$API/"
+    "$API/blog/"
+    "$API/blog/rss.xml"
+
+    "$MAIN/leak/"
+    "$APP/leak/leaker"
+
+    "$MAIN/nonexistent"
+    "$API/this-does-not-exist"
+)
+
+ROUTE_COUNT=${#ROUTES[@]}
+
+worker() {
+    local end=$((SECONDS + DURATION))
+    while [ $SECONDS -lt $end ]; do
+        curl -sk -o /dev/null "${ROUTES[$((RANDOM % ROUTE_COUNT))]}" 2>/dev/null || true
+        sleep "0.0$((RANDOM % 5 + 1))"
+    done
+}
+
+echo "Sending traffic for ${DURATION}s with ${CONCURRENCY} concurrent workers..."
+echo "Press Ctrl+C to stop early."
+
+pids=()
+for ((i = 0; i < CONCURRENCY; i++)); do
+    worker &
+    pids+=($!)
+done
+
+trap 'kill "${pids[@]}" 2>/dev/null; exit 0' INT TERM
+
+wait "${pids[@]}" 2>/dev/null
+echo "Done."

docs/index.md

@@ -11,6 +11,7 @@ Ember is a real-time monitoring tool for [Caddy](https://caddyserver.com/) and [
 - [CLI Reference](cli-reference.md): Flags, subcommands, keybindings, and shell completions
 - [JSON Output](json-output.md): Streaming JSONL mode for scripting
 - [Prometheus Export](prometheus-export.md): Metrics endpoint, health checks, and daemon mode
+- [Plugins](plugins.md): Building custom plugins for Ember
 - [Docker](docker.md): Running Ember in a container
 - [AI Agent Skills](skills.md): Skills for AI coding agents (Claude Code, Cursor, Copilot, etc.)
 - [Troubleshooting](troubleshooting.md): Common issues and how to resolve them